Let's see if we can work though some of your points one at a time and come to some kind of agreement:
Steel weighs around 495 pounds per cubic ft, Douglas fir around 35 lbs per cubic foot. Steel has a tensile and compression strength of 60,000 PSI , fir around 1500
The 3/16th steel plate I use on my boats has 2.5 times the weight of 1 inch fir and 7.5 times the tensile strength, giving steel a tensile and compression strength to weight ratio three times that of douglas fir. That is why big ships are no longer made of wood .
When engineers talk about the strength or stiffness of a hull skin material, tensile strength and compression strength are only a small part of the equation. From an engineering standpoint, there are a couple formulas that quantify the strength or stiffness of a hull skin material. For bending the formula is Fb (allowable stress in bending) times S (section modulus) and for stiffness it is E (modulus of elasticity) times I (moment of inertia). The formula for 'S' for a rectangular shape like plating is [B (width of the section) times D squared] divided by 6. The formula for 'I' for a rectangular shape like plating is [B (width of the section) times D (depth of the section) cubed] divided by 12. (I will be showing formulas and results below. Please feel free to check my calculations and assumptions)
So, for comparison 3/16" plating weighs 7.73 lbs per square feet. The same weight per square foot fir would be 2.65" thick. But to produce a fir hull skin with optimized performance in bending, sheer, and impact, the hull would be laminated and would ideally have a kevlar/vinylester sheathing material. Allowing for adhesives and the sheathing, fir hull that weighed the same as 3/16" steel plate would be closer to 2 1/4" thick in thickness.
The section modulus for a 1 foot wide piece of 3/16" steel plate is 0.0703125
inches cubed. The section modulus for a 1 foot wide piece of 2 1/4" thick Fir (ignoring the structural properties of the sheathing) is 10.125 inches cubed. The moment of inertia for a one foot wide piece of 3/16" steel plate is 0.0066 inches to the fourth. The moment of inertia for a 1 foot wide piece of 2 1/4" thick Fir (ignoring the structural properties of the sheathing) is 11.3906 inches cubed.
The allowable bending stress for A-65 steel is 39 KSI (KSI means 1,000 lbs per square inch and 39 KSI is a very big number). Fb for douglas fir is only in the 1.35 KSI range. Similarly, the E (modulus of elasticity) for steel is 30,000 KSI, while the E for Douglas fir is only 1,400 KSI. Looking at these Fb and E numbers it is easy to think that steel has to be stronger.
But when you multiply out S x Fb the two materials, the S x Fb for the 3/16" steel plate comes out to 2,742 Lb.in. while the S x Fb for the 2 1/4" thick Fir comes out to 13,669 Lb.in., which means that the same weight Douglas Fir panel is actually 5 times stronger in bending.
Similarly, when you multiply out E x I for the two materials, the E x I for the 3/16" steel plate comes out to 198 K.sq.in., while the E x I for the 2 1/4" thick Fir comes out to 15,947 K. sq.in., which means that the same weight Douglas Fir panel is actually 80 times stiffer.
However, where steel really comes out ahead is toughness, the ability absorb impacts by stretching , instead of shattering on the first impact. That is why a 30 calibre bullet which can go thru 23 inches of douglas fir , can barely make it thru 3/8th inch mild steel plate. That is a test of impact resistance.
There is no doubt that steel is a tough material. You are also right that 2 1/4" douglas fir, in and of itself, will not do much to stop a bullet or offer much abrasion resistance.
But if for some reason, you really want your boat to stop a bullet, then the vinylester/kevlar sheathing on the fir hull will result in a much greater stopping power than a steel hull, which is why the military has switched almost exclusively to using kevlar for helmets, armor and skid pads on thier vehicles and aircraft, and is the reason that Kevlar/vinylester is considered the safest material for motorcycle helmets.
Kevlar used to be wildly expensive and hard to use, but it has come down in price enormously and between prepregging, and vaccuum bagging is actually a pretty easy material to use in this kind of application.
Now then, if the guiding criteria is being able to abraid against coral or a rock for long periods of time, then steel probably is the right choice. But if the goal is to produce a lighter and stronger boat which can withstand an impact with a shipping container, or other sharp immovable object, and to survive a hard grounding on a rocky shore for a reasonable period of time, then I suggest that the laminated fir with vinylester/kevlar sheathing may be a better way to go.
Water flowing across a chine, does so at a very shallow angle. As water across a chine runs at a very shallow angle to the chine, it doesn't take much of a radius to eliminate any resulting turbulence there.
That basically agrees with my point on the comparatively flat angle chines seen on some origami designs. Where we may need to agree to disagree is on the statement, "it doesn't take much of a radius to eliminate any resulting turbulence there."
If I had to rephrase that to be something that I could agree with, I would say something like, "it is unlikely to eliminate turbulence at the chines without fairing the hull transversely, but turbulance at the chine can be reduced to a point where it is effectively inconsequential on a heavy displacement cruising boat."
Unlike boats made of other materials, cleats don't work lose, and welded down deck gear and fittings never leak. In any kind of weather , she is as dry inside as a boat can be.
Here is where you and I do not agree. Properly installed hardware on fiberglass or properly built wooden boats does not 'work itself loose'. Its easy to reach that conclusion looking a production coastal cruisers, where there rarely are backing plates, potted fastening holes and lock bolts. And yes those steps require extra labor, but done properly fittings do not loosen up on their own.
On the other hand, I think you are right that no matter how good a job one does bedding fittings on these other materials, sooner or later they will leak and sooner or later they will need rebedding.
When you build a fibreglass or wooden hull and deck, you still have to go out and acquire cleats, mooring bitts, chain plates, hatches, hatch hinges, lifelines, bow roller, install engine mounts, tankage, anchor winch , heater, self steering, inside steering, etc., etc. , all of which is done, at a much lower cost, when you have finished all the metal work on a steel boat, making finished steel work a much bigger part of the total cost of the boat , compared to boat building in other materials
To me, this one seems just plain bogus. If an owner is considering whether to build a steel boat or a fir/composite boat, there is no reason that owner cannot chose to make his hardware in virtually the same manner on each. If that owner was going to fabricate his cleats, mooring bitts, chain plates, hatches, hatch hinges, lifelines, bow roller, engine mounts, tankage, anchor winches, heaters, self steering, etc from scrap steel or scrap stainless, there is no reason that same owner cannot fabricate everyone of those parts for his fir/composite boat, for virtually the same price.